• Korean Journal of Microbiology
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• v.40 no.3
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• pp.217-220
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• 2004

The effect of media composition and culture condition on mycelial growth and cordycepin (3'-deoxyadenosine) production was determined using Cordyceps spp. Among the strains of C. militaris and C. sinensis tested, C. militaris KCTC 6862, C. militaris DGUM 32003 and C. militaris KCTC 16932 were excellent for the production of cordycepin. The optimal temperature and pH for production of cordycepin were $24^{\circ}C$ and pH ranged from 6.0 to 10, respectively. Among various sources of carbon and nitrogen tested, glucose and tryptone were very excellent for the production of cordycepin, respectively. After 5days cultivation with 1% of tryptone with nitrogen source, 39mg/l of cordycepin was produced. However, addition of phosphorus sources reduced the production of cordycepin.

• Journal of the Korean Chemical Society
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• v.17 no.3
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• pp.224-228
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• 1973

In the fermentation for preparation of petroprotein by Rhodotorula sp. in $C_{12}{\sim}C_{14}$n-alkane mixture it was investigated how the effects due to the difference of chemical form of the nitrogen sources are, that is, how the inorganic nitrogen sources such as nitrates and ammonium salts and organic nitrogen source such as urea effect on the view of fermentation time and yield and how the ratios of nitrogen to carbon with $NaNo_3$ effect. Then following results were obtained: the time required to maximum growth, when $NaNo_3$ or $(NH_4)_2SO_4$ was used as nitrogen source, was 40 hrs. and 45 hrs., respectively, but when urea was used, it was 66 hrs. much longer than above nitrogen sources. On the view of yield, however, in use of the both inorganic sources, when the yield is represented as consumption of 0.1 N-NaOH, it was 0.36 and 0.38 ml, respectively, but, in the case of urea, it amounted to 0.78 ml. In the effect of the ratios of nitrogen to carbon in medium, when n-alkane mixture was added in 1 % (vol.) and N/C with $NaNo_3$ was 0.2 the best results were obtained and generally the higher the value of the ratio the better growth effects were shown.

• Entomological Research
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• v.48 no.6
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• pp.480-489
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• 2018

Due to the increasing interest in natural biopolymers including chitin, the exploitation of economic and easily accessible chitin sources with good physicochemical properties is nowadays required. In view of this fact, in the current study chitin was extracted and physicochemically characterized from six Cicadas (Hemiptera: Homoptera: Cicadoidea) species collected from Mediterranean region of Turkey (2014-15). Chitin was extracted using a classic extraction method that includes acid and base treatment. TGA results revealed a remarkable increase ($410-412^{\circ}C$) for all the six Cicada species compared to other chitin samples extracted from various sources. For all of the six selected species the chitin contents on the dry basis were determined as 6.7% for Cicadatra atra, 5.51% for C. hyalina, 8.84% for C. platyptera, 4.97% for Cicada lodosi, 6.49% for C. mordoganensis, and 5.88% for Cicadetta tibialis. The surface morphology of chitin isolates from Cicada species was observed to consist of nanofibers and nanopores.

• The Plant Pathology Journal
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• v.23 no.2
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• pp.103-105
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• 2007

Mechanical transmission of barley seedlings with barley yellow mosaic virus (BaYMV) is generally inefficient and is the major constraint for testing cultivar resistance to the virus. To explore mechanical transmission, BaYMV-infected barley plants were grown at different conditions and used as inoculum sources to seedlings of susceptible barley cultivar Baegdong. Extracts prepared from BaYMV-infected Baegdong plants at 47, 53, 74, and 90 days after symptom appearance (DASA) and grown at 10 and $12^{\circ}C$ gave 10, 30, 68 and 76% infection, respectively on inoculated susceptible barley cv. Baegdong seedlings. While Jinyangbori, another susceptible cultivar obtained 95% infection rate inoculated with extracts from 90 DASA disease source and grown at $10/12^{\circ}C$. However, low infection rates were obtained when the virus sources were grown in a greenhouse at $15-18^{\circ}C$. Our results indicate that longer incubation period and lower temperature are required for virus accumulation and stability.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.06a
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• pp.811-812
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• 2007

• Clinical and Experimental Reproductive Medicine
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• v.27 no.1
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• pp.1-7
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• 2000

Objective: Mammalian embryos undergo changes of energy environment for transfer from oviduct to uterus. Also, the human reproductive organ (oviduct, uterus) contains energy sources of different concentration (oviduct - glucose: 0.5 mM, pyruvate: 0.32 mM, lactate: 10.5 mM; uterus - goucose: 3.15 mM, pyruvate: 0.1mM, lactate: 5.87 mM, respectively). This study was conducted to examine the effect of these energy sources added in DMEM with glutamine on the mouse embryo development. Methods: There was used ICR female mouse. Two cell embryos of mouse are collected by method of 'flushing'. Flushing fluid was used Ham's F-10 added to 20% FBS. The collected 2 cell embryos were cultured in media such as Control (only DMEM), group A and B (DMEM supplemented with 0.5 mM and 3.15 mM glucose), and group C and D (DMEM supplemented with 0.1 mM and 0.32 mM pyruvate), and group E and F (DMEM supplemented with 5.87 mM and 10.5 mM lactate). All experimental media supplemented with 20% hFF, respectively. Pattern of embryo development was observed to interval at 24hr during 96hr. Results : The media with glutamine added glucose (group A: 51.0%; group B: 48.4%) was significantly (p<0.05) higher than other experimental group in development into the morula stage after 24 hr in culture, but not significantly different compared with control and the rate of development into the blastocyst was significantly (p<0.05) low in the both of pyruvate (group C: 7.9% group D: 6.8%) and lactate (group E: 7.1%, group F: 7.1%) treatment group after 48 hr in culture. Development into the blastocyst and hatched balstocyst after 72 hr in culture revealed similarly in control (81.9%) and glucose treatment group (group A: 83.3%, group B: 82.8%). However, development into the hatched and attached blastocyst after 96hr in culture revealed significantly (p<0.05) development in the glucose treatment group (group A: 82.3%, group B: 78.5%) than control (63.2%), and its of pyruvate (group C: 34.1%, group D: 34.1%) and lactate (group E: 25.9%, group F: 33.3%) treatment group were significantly (p<0.05) lower than control similar to previous observations. Conclusion : The glucose added to the DMEM with only glutamine, as energy source, was highly to the rate of development compared with control, but the other energy sources were not, synthetically. Above refer to, the human reproductive organ (oviduct, uterus) contains energy sources of different concentration. Thus, further studies are will examine continuously to effects by interaction of different energy sources in the mouse embryo development, and these results will provide to foundation on the human embryo culture.

• Journal of Aquaculture
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• v.12 no.1
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• pp.47-56
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• 1999

Denitrification by anaerobic bacteria is one of the most common processes of removing nitrate from recirculating aquaculture systems. This process is affected by many factors such as external carbon sources, hydraulic retention time (HRT), and $COD/NO_3-N$ ratio. Although external organic carbon sources are essential for the denitrification process, these also contribute to increase dissolved organic carbon concentration in recirculating aquaculture systems. So these external organic carbons must be removed from the systems. This study was conducted to find out the optimum operating conditions for the removal of external organic carbons in a submerged denitrification biofilter. Combinations of two external carbon sources (glucose and methanol), two HRT (4- and 8-hour), and four different C:N ratios (3, 4, 5, and 6) were used in this experiment. The removal efficiencies of organic carbon sources at 8-hour HRT were always better than those at 4-hour's (P<0.05). Maximum removal efficiencies were achieved when C:N ratio was 5 in both glucose and methanol. The removal efficiencies of methanol were always better than those of glucose. The maximum removal efficiencies of glucose and methanol were 76.5% and 84.0%, respectively and the removal rates were 223.5 $g/m^2/day$ and 247.1$g/m^2/day$. The maximum removal rates of glucose (290.9 $g/m^2/day$) and methanol (355.6 $g/m^2/day$) were achieved at 4-hour HRT and 5 C:N ratio. But the concentrations of SCOD in the effluent of both glucose ($52.5 mg/\ell$) and methanol ($40.9 mg/\ell$) were too high for rearing fish. Therefore, the optimum operating conditions for the removal of external carbon in a submerged denitrification biofilter were 8-hour HRT and 5 C:N ratio. And methanol showed better efficiency as an external carbon sources.

• The Korean Journal of Mycology
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• v.29 no.1
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• pp.52-60
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• 2001

This study was carried out to obtain the basic data on artificial culture of Hohenbuehelia petaloides. The optimum medium are glucose peptone medium (GP), Hennerberg medium, Phellinus igniarius medium (PIM), Lentinus edodes medium (LEM), Czapek dox medium. The optimum condition for the mycelial growth was $30^{\circ}C$ and pH 6.0. The carbon sources such as dextrine, fructose and lactose were favorable to mycelial growth. The optimal concentrations of carbon sources are 10% dextrin and fructose. As nitrogen sources, tryptone, casamino acid and histidine appeared to be favorable. The optimal concentrations of nitrogen sources are 1% soy tone and 0.3% ammonium nitrate. The optimal concentration of yeast extract is 0.4%. The mineral nutrients of $KH_2PO_4$, $K_2HPO_4\;and\;MgSO_4{\cdot}7H_2O$ were effective and the optimal concentrations were 0.046, 0.1 and 0.05%, respectively.

• KIEE International Transactions on Electrophysics and Applications
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• v.3C no.1
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• pp.5-9
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• 2003

The waveforms of partial discharges (PDs) imply physical and structural properties of PD sources, so analyzing them give us information on the kind of PD sources and the location. Waveforms of PD as a time series function have variable amplitudes but sustain a certain uniform shape, which shows well the characteristics of the waveforms and frequency region. They can also be used as parameters having time and frequency information of PD signals and applied to classification of multiple PDs sources via Artificial Neural Network with back propagation (BP) learning.

• Journal of Korean Society on Water Environment
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• v.40 no.2
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• pp.67-78
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• 2024

The introduction of a significant amount of phosphorous into aquatic environments can lead to eutrophication, which can in turn result in algal blooms. For the effective management of watersheds and the prevention of water quality problems related to nonpoint organic matter (OM) sources, it is essential to pinpoint the predominant OM sources. Several potential OM sources were sampled from upper agricultural watersheds, such as fallen leaves, riparian reeds, riparian plants, paddy soil, field soil, riparian soil, cow manure, and swine manure. Stream samples were collected during two storm events, and the concentrations of dissolved organic carbon (DOC) and phosphorous (DOP) from these OM sources and stream samples were assessed. DOM indicators using fluorescence spectroscopy, including HIX, FI, BIX, and EEM-PARAFAC, were evaluated in terms of their relevance in discerning DOM sources during storm events. Representative DOM descriptors were chosen based on specific criteria, such as value ranges and pronounced differences between low and high-flow periods. Consequently, the spectral slope ratio (S_R) paired with fluorescence index (FI) using end-member mixing analysis (EMMA) proved to be suitable for estimating the contribution of organic carbon (OC). The contribution of each organic phosphorous (OP) in stream samples was determined using the phosphorous-to-carbon (P/C) ratio in conjunction with the OC contribution. Notably, OP derived from swine manure in stream samples was found to make the most dominant contribution, ranging from 61.3% to 94.2% (average 78.1% ± 12.7%). The results of this research offer valuable insights into the selection of suitable indicators to recognize various OM sources and highlight the main sources of OP in forested-agricultural watersheds.